A randomized comparison of oral and intravaginal misoprostol for labor induction

Objective: To compare oral misoprostol (100 mu g) to vaginal misoprostol (2 5 mu g) for cervical ripening and labor induction. Methods: Two hundred thirty-six women with medical or obstetric indications for labor induction and undilated, uneffaced cervices were assigned random ly to receive 100 pg of oral or 25 mu g of vaginal misoprostol every 4 hour s for 24 hours. Intravenous oxytocin was then given using a standardized pr otocol. We anticipated that 31% of women treated orally and 50% of women tr eated vaginally would deliver vaginally within 24 hours of starting labor i nduction. Results: Among 234 subjects, 121 received oral and 113 received vaginal mis oprostol. The mean (a standard deviation [SDI) interval from start of induc tion to delivery was 1240 +/- 845 minutes for orally treated women and 1381 +/- 802 minutes for vaginally treated women (P = .06, log-transformed data ). More orally treated women delivered vaginally in 24 hours than vaginally treated women (74 versus 54, P = .14, relative risk [RR] 1.14, 95% confide nce interval ICI] 0.92, 1.40). One hundred six women (87.6%) who received o ral misoprostol delivered vaginally, compared with 88 women (77.9%) who rec eived vaginal misoprostol (P = .07). Oxytocin was given to 60 (49.6%) orall y treated and 59 (52.2%) vaginally treated subjects (P = .69). More women i n the oral group had tachysystole, nine compared with two (P = .06), hypert onus, and hyperstimulation. Frequencies of intrapartum complications and bi rth outcomes were similar between groups. Conclusion: Oral misoprostol 100 mu g and vaginal misoprostol 25 pg were si milarly effective for cervical ripening and labor induction. Oral administr ation was associated with trends toward higher likelihood of vaginal delive ry and more uterine tachysystole. (Obstet Gynecol 2000;95: 905-8. (C) 2000 by The American College of Obstetricians and Gynecologists).